The invention relates to a testing device for the ultrasonic inspection of barstock. Such type testing devices are known in a variety of realizations; by way of example the reader is referred to the DE-book xe2x80x9cWerkstoffprxc3xcfung mit Ultraschallxe2x80x9d (xe2x80x9cMaterial Inspection with Ultrasoundsxe2x80x9d), 4th edition, by the authors J. Krautkrxc3xa4mer and H. Krautkrxc3xa4mer.
The inspection of barstock more specifically involves detection of internal flaws and of surface flaws but also comprises the testing of the dimensions. It is known that for ultrasonic inspection a water path is to be provided and maintained between the ultrasonic probe and the bar to be tested. Several techniques are known to achieve this such as e.g., immersion testing, partial immersion testing or inspection by means of a guided water jet. Further, closed water tanks exist, which are often termed SPS and through which the test samples are conveyed. After the test sample has entered the closed water tank, the test sample seals the tank inlet and outlet. The water tank is filled with water in order to achieve the coupling between the probe and the test sample. The probes may thereby be disposed in a circumferential symmetry. The disadvantage thereof is the quite long time needed for the tank to be filled with water, end portions remaining untreated. Further, air bubbles in the coupling water compromise the inspection.
Rotary testing devices are moreover known. Rotation of the entire testing chamber together with the probes permits to generate a stable water jacket. Through sealing systems disposed on the inlet and on the outlet side a substantially tubular water jacket through which the test samples can be conveyed is obtained. This type of testing technique has a high testing efficiency but also involves high mechanical expense because of the rotating testing chamber. The term xe2x80x9cbarstockxe2x80x9d is to be construed herein after as any kind of elongated material, more specifically round steel bars, bars with non round profiles such as square and hexagonal bars, flat material in the form of rods, but also tubes and rolling stock, extruded profiles.
It is the object of the invention to indicate a device for the ultrasonic inspection of barstock that has the advantages of the above mentioned rotary testing device but which is mechanically simple in construction, which requires little preparation prior to ultrasonic inspection and in which the probes can be disposed anywhere on the circumference.
This objective is accomplished by a testing device for the ultrasonic inspection of barstock a) with a stationary tank defining a substantially cylindrical interior space that has a larger diameter than the barstock and is provided with a cylinder""s axis, b) with an equipment for producing a surrounding water jacket, said equipment being provided with either at least one nozzle for a water supply which is disposed in substantially tangential contact with an inner lining of the interior space into which it discharges and/or a blade wheel that is disposed so as to rotate about the cylinder""s axis and that is assigned a rotary drive mechanism and c) with at least one ultrasonic probe that is connected to the tank and has an active face which is freely accessible from the cylindrical interior space.
Water is introduced through the nozzle which is in tangential contact and discharges into the interior space of the tank. Through this supply line and the resulting rotational movement of the water a substantially tubular water jacket is obtained. Unwanted air bubbles do not remain stationary but are swept along and are therefore insignificant in testing. The tank does not rotate, it rather remains stationary. What rotates though is the water jacket within the tank. As the water jacket rotates it is stable so that testing may be carried out immediately after a test sample in the form of a bar has entered. The rotating water jacket may be as well produced by the blade wheel. The term xe2x80x9cblade wheelxe2x80x9d is to be construed as any arrangement of blades, which are oriented in a more or less radial direction, that is capable of moving the water within the tank in such a manner that the revolving water jacket is obtained. The blade wheel is preferably disposed on front faces. It may be substituted for the front faces. The blade wheels are preferably positioned outside the ultrasound path of the at least one ultrasonic probe. It is also possible though that the ultrasonic probes emit sound energy through the range of movement of the blades of a blade wheel. In this case, they are matched to the movement of the blade wheel in such a manner that a measurement only occurs when there is no blade wheel in the ultrasound path.
The tank may have a very short structure. Untested end portions remain small. It is however also possible to perform the final testing inside the tank if there is an end region of a bar to be tested in the interior space.
At least one ultrasonic probe is disposed on the tank, a great multitude of probes is preferably provided for. They can be disposed anywhere on the circumference. Probe clusters or probe arrays can also be utilized. Accordingly, they can be oriented radially or inclined at any angle within the possible ultrasonic emission angles, e.g., inclined in the radial plane or at an angle different from 90 degrees to the cylinder""s axis.
The ultrasonic probes have an active face that is preferably formed by a leading body made from an appropriate solid material. Said leading body may be formed in such a manner that it is made flush with the tank, i.e., that it does not impair the rotation of the water within the tubular tank.
The parts to be tested are conveyed through the interior space in a direction that is substantially concentric with the cylinder""s axis. It is however also possible to inspect stationary bars or profiles by having the tank made from two shells that are to be joined together in an axial plane, are placed around a stationary bar, a tube for example, and can be axially displaced in order to perform the inspection.
Guide means for the barstock are provided on the two front faces of the tubular tank and are devised for guiding the bar to be tested so that the bar to be tested is positioned in such a manner that it is substantially concentric with the cylinder""s axis. Suited sealing means are preferably provided for keeping the exit of water in the region of the front faces low. It is however also possible to deliberately have the water exiting in the region of the front faces so that the seals can be very simple or even dispensed with on the one side and that no separate outlet is required on the other side. A separate outlet may be provided for though, said outlet being configured according to the at least one nozzle for water supply and allowing the water to exit tangentially in the direction of rotation.
For sealing the region of the front faces, replaceable end rings that can be readily removably fastened to the two front faces of the tank have proved particularly efficient. They exist in various realizations, i.e., with differing central openings that are adapted to the respective one of the barstock to be tested, namely to the profile thereof.
In the region of the front faces, at the site where the end rings are disposed, water may, possibly is even intended to, exit. Collecting basins for collecting the exiting water are therefore disposed beneath the front faces.